test(worksheet): pin simulated case 43 at 1e-4 (RR + dry-line + mixed roof)

Golden regression fixture for the multi-feature dwelling that surfaced the
two Elmhurst-extractor bugs in a33707f8. case 43 is a 2-BP mid-terrace with
a DETAILED room-in-roof (two slopes, two flat ceilings, party + exposed
gables, two common walls), a MIXED-insulation multi-section roof (Main
insulated + Extension uninsulated 2.30), a DRY-LINED extension solid wall,
a mains-gas boiler (102 / control 2106) and a House-coal solid-fuel
secondary (633).

Routes the Summary PDF through the WHOLE extractor + mapper + calculator
pipeline (no hand-built EpcPropertyData) and pins the §3 fabric + SAP-rating
block at abs=1e-4: (29a) walls 74.5800, (30) roof 38.5008, (33) fabric
172.7844, continuous SAP 73.2332 = (258), CO2 3518.3037 = (272). Guards the
detailed-RR slope/common_wall surfaces, the dry-lining R=0.17 adjustment,
and the per-part mixed-roof billing together. Summary mirrored to
backend/documents_parser/tests/fixtures/Summary_001431_case43.pdf; provider
module mirrors the _case6/_case21 pattern, assertion in
test_section_cascade_pins. Harness 47/47; regression = the 3 pre-existing
fails; pyright net-zero.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/domain/sap10_calculator/worksheet/_elmhurst_worksheet_001431_case43.py

@@ -0,0 +1,116 @@
+"""Mapper-driven cascade pin against the Elmhurst P960-0001-001431
+"simulated case 43" worksheet — a 2-storey mid-terrace deliberately built to
+exercise every feature in one dwelling:
+
+  - a DETAILED room-in-roof on the Main BP (two slopes, two flat ceilings,
+    a party + an exposed gable, two common walls) — exercises the
+    slope / stud / common_wall detailed-RR surfaces end-to-end;
+  - a MIXED-insulation multi-section roof (Main insulated 0.16/0.54/0.68/0.11
+    + Extension uninsulated 2.30);
+  - a DRY-LINED extension solid wall (RdSAP 10 §5.8 Table 14 R=0.17:
+    solid brick 1.70 -> 1.32);
+  - a mains-gas boiler (SAP 102, control 2106 interlock) with a House-coal
+    solid-fuel SECONDARY (633, 60%) and a 210 L declared-loss cylinder.
+
+This case was generated to settle the room-in-roof + mixed-roof + secondary
+feature set with a single 1e-4 pin. It exposed two compensating Elmhurst-
+extractor bugs (commit `a33707f8`) whose fabric errors nearly cancelled
+(walls net -0.76 W/K, hidden behind a +0.05 SAP delta):
+  1. the main/extension wall "Dry-lining: Yes" line was read only for
+     ALTERNATIVE walls -> the dry-lined extension wall billed at the
+     un-adjusted 1.70 instead of 1.32;
+  2. the LAST room-in-roof surface row's per-row token scan over-read into
+     the next section -> Common Wall 2's default U silently zeroed
+     (1.90 -> 0.00).
+With both fixed the whole §3 fabric and the SAP/CO2 reproduce EXACTLY.
+
+Like 000565 / the _rr cases / case 20 / 21 / 38 / 39, this fixture does NOT
+hand-build the EpcPropertyData: it routes the Summary PDF through
+ElmhurstSiteNotesExtractor + from_elmhurst_site_notes so the pin exercises
+the WHOLE extractor + mapper + calculator pipeline.
+
+Source: user-simulated PDFs at `sap worksheets/golden fixture debugging/
+simulated case 43/`. The Summary is mirrored into the tracked
+`backend/documents_parser/tests/fixtures/Summary_001431_case43.pdf` so the
+test runs without depending on the unstaged workspace.
+
+Worksheet pin targets (P960-0001-001431, "11a. SAP rating" / "12a. CO2
+emissions" block — the UK-average-climate rating block our cascade
+reproduces):
+- SAP value (un-rounded, before (258) integer rounding) = 73.2332 (band C)
+- (272) Total CO2, kg/year                              = 3518.30
+
+Per [[feedback-zero-error-strict]] + [[feedback-continuous-sap-tolerance]]:
+pins are abs <= 1e-3 against the worksheet PDF (printed to 4 dp).
+"""
+
+from __future__ import annotations
+
+import re
+import subprocess
+from pathlib import Path
+from typing import Final
+
+from backend.documents_parser.elmhurst_extractor import ElmhurstSiteNotesExtractor
+from datatypes.epc.domain.epc_property_data import EpcPropertyData
+from datatypes.epc.domain.mapper import EpcPropertyDataMapper
+
+# parents[0]=worksheet/, [1]=sap10_calculator/, [2]=domain/, [3]=tests/,
+# [4]=repo root.
+_SUMMARY_PDF: Final[Path] = (
+    Path(__file__).resolve().parents[4]
+    / "backend" / "documents_parser" / "tests" / "fixtures"
+    / "Summary_001431_case43.pdf"
+)
+
+LINE_29A_WALLS_W_PER_K: Final[float] = 74.5800
+# (30) = ΣA×U: FlatCeil1 4.3200 + FlatCeil2 6.9000 + Slope1 1.0200 +
+# Slope2 0.1408 + roof Main 3.1200 + roof Ext1 (uninsulated) 23.0000.
+LINE_30_ROOF_W_PER_K: Final[float] = 38.5008
+LINE_33_FABRIC_W_PER_K: Final[float] = 172.7844
+LINE_258_SAP_VALUE_CONTINUOUS: Final[float] = 73.2332
+LINE_272_TOTAL_CO2_KG_PER_YR: Final[float] = 3518.3037
+
+
+def _summary_pdf_to_textract_style_pages(pdf_path: Path) -> list[str]:
+    """Convert a Summary PDF into the per-page text format the
+    ElmhurstSiteNotesExtractor expects (label/value token sequences).
+    Mirror of the helper in the other `_elmhurst_worksheet_*` fixtures.
+    """
+    info = subprocess.run(
+        ["pdfinfo", str(pdf_path)], capture_output=True, text=True, check=True,
+    ).stdout
+    m = re.search(r"Pages:\s+(\d+)", info)
+    if m is None:
+        raise RuntimeError(f"Could not parse page count from {pdf_path}")
+    page_count = int(m.group(1))
+    pages: list[str] = []
+    for i in range(1, page_count + 1):
+        layout = subprocess.run(
+            [
+                "pdftotext", "-layout", "-f", str(i), "-l", str(i),
+                str(pdf_path), "-",
+            ],
+            capture_output=True, text=True, check=True,
+        ).stdout
+        tokens: list[str] = []
+        for line in layout.splitlines():
+            if not line.strip():
+                tokens.append("")
+                continue
+            parts = [p for p in re.split(r"\s{2,}", line.strip()) if p]
+            tokens.extend(parts)
+        pages.append("\n".join(tokens))
+    return pages
+
+
+def build_epc() -> EpcPropertyData:
+    """Route the simulated case-43 Summary through extractor + mapper.
+    No hand-built EpcPropertyData — the extractor and mapper are part of
+    the test target. This module is a pin PROVIDER (build_epc + LINE_*
+    constants, mirroring `_elmhurst_worksheet_001431_case6` / `_case21`);
+    the collected assertion lives in
+    `test_section_cascade_pins.test_case43_*`."""
+    pages = _summary_pdf_to_textract_style_pages(_SUMMARY_PDF)
+    site_notes = ElmhurstSiteNotesExtractor(pages).extract()
+    return EpcPropertyDataMapper.from_elmhurst_site_notes(site_notes)

tests/domain/sap10_calculator/worksheet/test_section_cascade_pins.py

@@ -44,6 +44,7 @@ from tests.domain.sap10_calculator.worksheet import (
     _elmhurst_worksheet_000516 as _w000516,
     _elmhurst_worksheet_001431_case6 as _w001431_case6,
     _elmhurst_worksheet_001431_case21 as _w001431_case21,
+    _elmhurst_worksheet_001431_case43 as _w001431_case43,
 )
 
 
@@ -328,6 +329,47 @@ def test_section_3_wall_u_by_thickness_case21_match_pdf() -> None:
     )
 
 
+def test_case43_detailed_rr_dryline_and_mixed_roof_match_pdf() -> None:
+    """Full-feature pin for simulated case 43 — a 2-BP mid-terrace with a
+    DETAILED room-in-roof (slopes + flat ceilings + party/exposed gables +
+    common walls), a MIXED-insulation multi-section roof (Main insulated +
+    Extension uninsulated), a DRY-LINED extension solid wall (RdSAP 10 §5.8
+    Table 14: 1.70 -> 1.32), a mains-gas boiler (102, control 2106) and a
+    House-coal solid-fuel secondary (633). Exposed + regression-guards two
+    compensating Elmhurst-extractor bugs (commit a33707f8): the unread
+    main-wall dry-lining and the last-RR-row default-U over-read, whose
+    fabric errors nearly cancelled (walls net -0.76). With both fixed the
+    §3 fabric and the SAP-rating block reproduce the P960 exactly."""
+    # Arrange
+    from domain.sap10_calculator.calculator import calculate_sap_from_inputs
+
+    epc = _w001431_case43.build_epc()
+
+    # Act
+    ht = heat_transmission_section_from_cert(epc)
+    result = calculate_sap_from_inputs(cert_to_inputs(epc))
+
+    # Assert — §3 fabric (the RR + dry-lining + mixed-roof fixes) and the
+    # SAP-rating block, each at abs=1e-4.
+    _pin(ht.walls_w_per_k, _w001431_case43.LINE_29A_WALLS_W_PER_K, "§3 (29a) case43")
+    _pin(ht.roof_w_per_k, _w001431_case43.LINE_30_ROOF_W_PER_K, "§3 (30) case43")
+    _pin(
+        ht.fabric_heat_loss_w_per_k,
+        _w001431_case43.LINE_33_FABRIC_W_PER_K,
+        "§3 (33) case43",
+    )
+    _pin(
+        result.sap_score_continuous,
+        _w001431_case43.LINE_258_SAP_VALUE_CONTINUOUS,
+        "(258) case43",
+    )
+    _pin(
+        result.co2_kg_per_yr,
+        _w001431_case43.LINE_272_TOTAL_CO2_KG_PER_YR,
+        "(272) case43",
+    )
+
+
 def test_case6_main_2_emitter_and_control_extracted() -> None:
     """Simulated case 6's §14.1 Main Heating2 lodges its OWN emitter
     ("Underfloor Heating") and control ("SAP code 2110, ...") — the two